Muffler with inner flexible corrugated conduit



N ov. 7, 1950 J. J. THOMAS 2,528,674

MUFFLER WITH INNER FLEXIBLE CORRUGATED CONDUIT Filed Sept. 7, 1948 3 Sheets-Sheet 1 E J f3/ LE Z5 n JOSEPH J. THOMAS ATTORNEYS Nov. 7, 1950 J. J. THOMAS 2,528,674

MUFFLER WITH INNER FLEXIBLE GORRUGATED CONDUIT Y Filed Sept. '7, 1948 3 Sheets-Sheet 2 Iii# V26 Y" if IN VEN TOR.

JOSEPH J. THOMAS Wil/vvv, KM

ATT RNEYS Nov. 7, 1950 J. J. THOMAS 2,528,674

MUFFLER WITH INNER FLEXIBLE CORRUGATED CONDUIT Filed Sept` 7, 1948 5 Sheets-Sheet 5 .73 Z9 5 l J tl, ,ff f

f5 l Anf A j ENToR.

Q JOSEPH J THOMAS fw {'g BY WMM/'MVM AT 'roRNr-:YS

Patented Nov. 7, 1950 MUFFLER WITH INNER FLEXIBLE CORRUGATED CONDUIT Joseph J Thomas, Los Angeles, Calif.

Application September 7, 1948, Serial No. 47,969

Claims.

The present invention relates to a muffler for exhaust gases, and has particular reference to improvements over the muffler disclosed in my copending application, Serial No. 647,033, filed in the United States Patent Ofce on February 12, 1946:, now Patent 2,450,212, issued September 28, 1948. It consists of the combinations, constructionsand arrangement of parts, as hereinafter described and claimed.

An object of my invention is to provide a muffler for exhaust gases, which will reduce materially the amount of smoke exhausting from the tail pipe of the muffler. At the same time, the loud cracking noises are practically eliminated, without creating back pressure on the engine. Further, the outer shell of the muflier is cool when the engine is operating, thus eliminating fire hazard.

More specifically described, I provide a muiler having inner and outer shells arranged in spaced relation with one another to form an air space therebetween. Air is drawn through this space during operation of the muffler, which serves to cool the outer shell. Also, this air is introduced into a combustion zone provided interiorly of the inner shell, where it furnishes oxygen to assist in burning the unused gases and smoke passing through the muiiler from an engine,

Flexible or corrugated tubes are provided in the muiller to impart a whirling motion to gases and air passing therethrough. This whirling motion insures intermixing of the gases and air; also, it encourages a more even flow. This has a tendency to reduce the noise. These tubes are arranged in such a manner as to permit them to expand and contract without breaking the welding that anchors them in place, or disturbing funnel-shaped cones associated with these flexible or corrugated tubes.

Other objects and advantages will appear as the specication continues, and the novel features of the invention will be set forth in the claims hereunto appended.

For a better understanding of this invention, reference should be had to the accompanying drawings, forming part of this application, in which:

Figure 1 is a side elevation of a muiiier constructed in accordance with my invention;

Figure 2 is a vertical sectional view of the lower portion of the same mufller, parts being shown in elevation;

Figure 3 is a vertical sectional view of the tail pipe illustrated in Figure 1, the flexible or corrugated tubes being disclosed in elevation;

Figures 4 and 5 are transverse sectional views taken along the lines IV-IV and V-V, respectively, of Figure 2;

Figure 6 is a horizontal sectional view taken 5 along the line VI-VI of Figure 3;

Figure '7 is a side elevation of a modified form of the muiiler, the tail pipe being shown partly in section;

Figure 8 is a vertical sectional view of the lower 10 part of the muler shown in Figure 7, portions being illustrated in elevation; and

Figure 9 is a horizontal sectional View taken along the line IX-IX of Figure 8,

While I have shown only the preferred forms of my invention, it should be understood that various changes, or modifications, may be made lwithin the scope of the annexed claims without departing from the spirit thereof.

Referring now to the first embodiment of my invention, as illustrated in Figures 1 to 6, in-

clusive, it will be noted that I provide an outer shell indicated generally at A. An inner shell B is mounted interiorly of the shell A in spaced relation therewith to provide an air space l therebetween. These two shells are Welded, or otherwise secured to a lower head 2. An upper head 2' is provided for the inner shell. Spacers 3 are interposed between the upper portions of the shells to permit air from the outside to enter the space l, as suggested by the arrows a in Figures 1 and 2. e

For the purpose of conveying hot exhaust gases from an engine exhaust pipe C to the interior of the shell B, I provide an inlet tube D. The latter pierces the lower head 2 and is fastened thereto by welding 4, or other suitable securing means. A reducing ring 5 is utilized for making a gas-tight connection between the exhaust pipe C and the inlet tube D.

In Figure 2, I disclose a funnel-shaped injection cone E disposed interiorly of the inner shell B, which is telescoped over the inlet tube D in spaced relation therewith. The larger end 6 of this injection cone ts against the inner surface of the shell B. This cone has an outlet opening l at its smaller end.

The upper end of the inlet tube D has a corrugated or flexible tube F connected thereto by a line of solid welding 8. This tube and inlet pipe provide a continuous conduit for hot exhaust gases 9. These gases are discharged from the upper open end Il] of the corrugated tube into a combustion Zone H of the injection cone E. It will be noted that the interior and exterior surfaces of the tube F are fashioned with spiral grooves l2 and i4, respectively. The drawing shows this tube as having double spiral grooves, but I do not desire to be limited in this respect.

As the hot exhaust gases 9 pass through the corrugated tube F, they are caused to whirl by the interior spiral grooves I2. In order to reduce the amount of smoke contained in the exhaust gases, air ducts G are provided for conveying air from thespace I for introduction into the combustion zone II.

The ducts have their inlet ends I5 communicating with the space i, while their discharge ends I6 are interposed between the injection cone E and the corrugated tube F. Air discharging from these ducts will flow along the outer spiral grooves I4, as suggested by the arrows b in Figure 2, and will be whirling at the time the air enters the combustion Zone Il. This will insure thorough mixing of the air and exhaust gases, resulting in burning the gases to a considerable extent.

"When the muiiler is assembled, the corrugated orflexibletubeF is pressedagainst the inside of the injection cone E, but is left unattached thereto. This allows the tube F to expand and contract without .breaking the welded joint 8 or in any way disturbing the cone E.

A Idischarge cone H is mounted interiorly of the inner shell B in axial alignment with the injection cone E. The cone H, also, is funnelshaped'and has its larger end Il contacting with the inner surface of the shell B. The outlet end .I8 of the .discharge cone H pierces the top head 2 of the inner shelland communicates with a tailxpipe J. The latter is welded to the top head l2'; at iii r(see Figure 2). '.The'outlet Lend .l of the injection cone E has acorrugated or flexible tube K connected thereto by a solid lineof we'ldZ. The outlet end 2l ofithistube is pressed against theinside of the discharge cone H, but is unattached thereto. This arrangement provides for expansion and contraction of the tubeK without breaking the weld 2l! or disturbing the discharge cone. The tube K is corrugated, and its inner spiral grooves 22 cause the exhaust gases to whirl as they pass therethrough. The whirling of the gases in the tubes.F and 'K encourages a more even flow. This has a tendency to reduce the noise.

"flhetailpipe .l` has a flange -23 welded thereto, as at 24. This flange overlies and is .spaced above the upper open end of the outer casing A. An air-adjusting ring L encircles the upper part of the casing A andv is adjustable toward and away from the iiange 23 to vary the amount of cold air drawn into the space i. This ring is retained in adjusted position by a clamping bolt 25. The cold air entering the space I will cool thelmuler and thus reduce fire hazards.

The interior construction of the tail pipe J is shown in Figure 3. Sections of corrugated or flexible tubes M are anchored in the tail pipe by welding 26. These tubes are fashioned with interior and exterior spiral grooves 2l and 28, respectively. As the exhaust gases pass upwardly through the tubes M, the interior grooves 2l cau-Se the gases to whirl. Part of the exhaust gases will fiowalong the exterior grooves 28, as suggested by Ithe arrows c in Figure 3. As the gases vpassing around the sections of corrugated tubes M intersect the gases flowing through .these tubes, a whirling motion is developed and the even flow created eliminates the cracking noises as the gases leavel the outlet 29 of the tail pipe. The welding 26 is arranged so as not to interfere with ilow of gases through the exterior grooves 28.

Having thus described the various parts of the rst embodiment of my muiiler, the operation thereof is summarized briefly as follows:

Assuming that the exhaust pipe C is connected to the inlet pipe D, the hot exhaust gases 9 will pass upwardly through the corrugated or flexible tube F. The interior spiral grooves I2 will cause the gases to whirl. Air is drawn from the space I through the ducts G, and after passing upwardly along the exterior grooves I 4 will enter the combustion zone Il in a whirling manner. This addition of air will cause a more complete combustion of the exhaust gases so as to reduce materially the amount of smoke escaping from the muilier.

The exhaust gases continue to flow upwardly and. are whirled again by the interior spiral grooves 22 as they pass through the corrugated 'or flexible tubeK,-causing a more even ow and further reducing the noise. Finally, the burnt gases flow through the outlet end I8 of the discharge cone H andr enter the tail pipe J.

As the exhaust gases encounter each of the sections -of corrugated or exble tubes M, part of these gases will flow through the interior thereof and a whirling action of gases developed by the interior spiral grooves 21. Some of the exhaust gases will flow around the tubes M, taking passage through the exterior spiral grooves 28. The whirling of the gases and intersecting of the `gas streams will produce a more even ow, and will result in eliminating practically al1 of the cracking noise.

The second embodiment of my invention, as exemplified in Figures '7,'8 and 9 is substantially the same as that shown in the rst form, excepting Yfor the omission of any corrugated or flexible tube on the top of the inlet pipe D and elimination of corrugated or exible tubes in the tallk pipe J. Accordingly, corresponding reference characters will be applied to designate like parts.

In Figures Sand 9, spacers 3B are welded to the upper end of the inlet pipe D and abut the interior surface of the injection cone E. These spacers serve to provide spaces 3| between the inlet pipe and the injection cone through which air can flow from the ducts G to the combustion zone I I. Otherwise, the operations of the two forms of muiiler .are identical.

Iclaim:

1. In a mufller of the character described; a

shell having an inlet pipe leading thereinto; a funnel-shaped injection cone disposed in the shellforreceiving exhaust gases from the inlet pipe at its large end and provided with an outlet end at its smaller end, all of the gases passing out through the smaller end; a funnel-shaped discharge cone mounted in the shell and having its large end contacting the shell a tail pipe communicating with the small end of the discharge cone; and a corrugated tube connected to the outlet end of thefinjection cone and bearing against the interior surface of the discharge cone; the tube being unattaohed to the discharge cone, whereby the tube can expand and contract Without breaking its connection with the injection cone.

2. In a muiiler of the character described; a shell having an inlet pipe leading thereinto; a funnel-shaped injection cone disposed in the shell for receiving exhaust gases from the inlet pipe and provided vwith an outlet end.; a funnel shaped discharge cone mounted in the shell and having a tail pipe communicating therewith; a corrugated tube connected to the outlet end of the injection cone and bearing against the interior surface of the discharge cone; the tube being unattached to the discharge cone, whereby the tube can expand and contract without breaking its connection with the injection cone; the injection cone telescoping over the inlet tube in spaced relation therewith; and at least one air duct extending throughout the length of the shell for cooling the latter and leading to the space between the injection cone and the corrugated tube for entraining of air into the stream of exhaust gases passing through the injection cone.

3. In a muiiler of the character described; a funnel-shaped injection cone provided with an outlet at its smaller end; a corrugated tube abutted against and connected to the smaller end of the injection cone; the tube and cone providing a continuous conduit; and an inlet tube for receiving exhaust gases, the tube having a helical grooved portion extending into the cone and contacting with its inner surface.

4. In a muiiier of the character described; a shell having an inlet pipe leading thereinto; a funnel-shaped injection cone disposed in the shell and provided with an outlet end; and a corrugated tube having one end thereof abutted against and connected to the inlet pipe; the .inlet pipe and tube providing a continuous conduit for exhaust gases; and the other end of the tube bearing against the interior surface of the injection cone, but unattached thereto, whereby the tube can expand and contract without breaking its connection with the inlet pipe.

5. In a muier of the character described; a shell having an inlet pipe leading thereinto; a funnel-shaped injection cone disposed in the shell and provided with an outlet end; a corrugated tube having one end thereof abutted against and connected to the inlet pipe; the inlet pipe and tube providing a continuous conduit for exhaust gases; and the other end of the tube bearing against the interior surface of the injection cone; but unattached thereto, whereby the tube can expand and contract Without breaking its connection with the inlet pipe; the interior of the tube having at least one spiral groove to develop a whirling motion for exhaust gases passing therethrough; the exterior of the tube having at least one spiral groove to provide an air passage- Way leading between the tube and the injection cone; and means for delivering air into the exterior groove on the tube for iiow through said passageway and entraining into the stream of exhaust gases.

JOSEPH J. THOMAS.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,302,300 Brinkman Apr. 29, 1919 1,658,402 Warth Feb 7, 1928 1,972,065 Noblitt Aug, 28, 1934 2,014,368 Blundell Sept. 17, 1935 2,122,086 Chase June 28, v1938 

